linux-stable/arch/x86
Borislav Petkov 4750a0d112 x86, microcode, AMD: Fix early ucode loading on 32-bit
Konrad triggered the following splat below in a 32-bit guest on an AMD
box. As it turns out, in save_microcode_in_initrd_amd() we're using the
*physical* address of the container *after* we have enabled paging and
thus we #PF in load_microcode_amd() when trying to access the microcode
container in the ramdisk range.

Because the ramdisk is exactly there:

[    0.000000] RAMDISK: [mem 0x35e04000-0x36ef9fff]

and we fault at 0x35e04304.

And since this guest doesn't relocate the ramdisk, we don't do the
computation which will give us the correct virtual address and we end up
with the PA.

So, we should actually be using virtual addresses on 32-bit too by the
time we're freeing the initrd. Do that then!

Unpacking initramfs...
BUG: unable to handle kernel paging request at 35d4e304
IP: [<c042e905>] load_microcode_amd+0x25/0x4a0
*pde = 00000000
Oops: 0000 [#1] SMP
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.17.1-302.fc21.i686 #1
Hardware name: Xen HVM domU, BIOS 4.4.1 10/01/2014
task: f5098000 ti: f50d0000 task.ti: f50d0000
EIP: 0060:[<c042e905>] EFLAGS: 00010246 CPU: 0
EIP is at load_microcode_amd+0x25/0x4a0
EAX: 00000000 EBX: f6e9ec4c ECX: 00001ec4 EDX: 00000000
ESI: f5d4e000 EDI: 35d4e2fc EBP: f50d1ed0 ESP: f50d1e94
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
CR0: 8005003b CR2: 35d4e304 CR3: 00e33000 CR4: 000406d0
Stack:
 00000000 00000000 f50d1ebc f50d1ec4 f5d4e000 c0d7735a f50d1ed0 15a3d17f
 f50d1ec4 00600f20 00001ec4 bfb83203 f6e9ec4c f5d4e000 c0d7735a f50d1ed8
 c0d80861 f50d1ee0 c0d80429 f50d1ef0 c0d889a9 f5d4e000 c0000000 f50d1f04
Call Trace:
? unpack_to_rootfs
? unpack_to_rootfs
save_microcode_in_initrd_amd
save_microcode_in_initrd
free_initrd_mem
populate_rootfs
? unpack_to_rootfs
do_one_initcall
? unpack_to_rootfs
? repair_env_string
? proc_mkdir
kernel_init_freeable
kernel_init
ret_from_kernel_thread
? rest_init

Reported-and-tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
References: https://bugzilla.redhat.com/show_bug.cgi?id=1158204
Fixes: 75a1ba5b2c ("x86, microcode, AMD: Unify valid container checks")
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # v3.14+
Link: http://lkml.kernel.org/r/20141101100100.GA4462@pd.tnic
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-01 20:24:21 +01:00
..
boot Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-23 14:45:09 -07:00
configs x86: Add "make tinyconfig" to configure the tiniest possible kernel 2014-08-08 16:30:24 -07:00
crypto Revert "crypto: aesni - disable "by8" AVX CTR optimization" 2014-10-02 14:40:28 +08:00
ia32 x86_64, entry: Fix out of bounds read on sysenter 2014-10-31 18:47:09 -07:00
include sched: stop the unbound recursion in preempt_schedule_context() 2014-10-28 10:46:05 +01:00
kernel x86, microcode, AMD: Fix early ucode loading on 32-bit 2014-11-01 20:24:21 +01:00
kvm KVM: x86: Wrong assertion on paging_tmpl.h 2014-10-24 13:30:37 +02:00
lguest asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
lib Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 18:14:50 +02:00
math-emu asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
mm x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE 2014-10-29 10:57:21 +01:00
net x86: bpf_jit: fix two bugs in eBPF JIT compiler 2014-10-14 13:13:14 -04:00
oprofile percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t 2014-08-28 08:58:57 -04:00
pci xen: features and fixes for 3.18-rc0 2014-10-11 20:29:01 -04:00
platform Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-31 14:30:16 -07:00
power nosave: consolidate __nosave_{begin,end} in <asm/sections.h> 2014-10-09 22:26:04 -04:00
purgatory arch/x86/purgatory/Makefile: try to use automatic variable in kexec purgatory makefile 2014-10-14 02:18:21 +02:00
realmode x86/build: Supress realmode.bin is up to date message 2014-04-16 15:17:24 +02:00
syscalls bpf: enable bpf syscall on x64 and i386 2014-09-26 15:05:14 -04:00
tools x86/relocs: Make per_cpu_load_addr static 2014-09-24 15:17:47 +02:00
um Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
vdso x86/vdso: Fix vdso2c's special_pages[] error checking 2014-09-24 09:55:38 +02:00
video
xen x86/xen: panic on bad Xen-provided memory map 2014-10-23 16:24:02 +01:00
.gitignore x86/build: Add arch/x86/purgatory/ make generated files to gitignore 2014-10-09 09:29:46 +02:00
Kbuild kexec: create a new config option CONFIG_KEXEC_FILE for new syscall 2014-08-29 16:28:16 -07:00
Kconfig perf/x86: Fix compile warnings for intel_uncore 2014-10-28 10:51:03 +01:00
Kconfig.cpu Merge branch 'x86-nuke-platforms-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-04-02 13:15:58 -07:00
Kconfig.debug x86/efi: Dump the EFI page table 2014-03-04 16:17:17 +00:00
Makefile Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 18:17:33 +02:00
Makefile.um
Makefile_32.cpu